The present invention relates to a method and system for promptly extinguishing fires in large buildings, such as skyscrapers.
Various laws and regulations exist relative to the extinguishing of fires and the escape of occupants of skyscrapers when a fire has started therein in order to save lives and prevent damage, such regulations seeking to prevent spread of fire in floors of a skyscraper above the floor in which a fire has started and providing wintermeasures against smoke and flame and means of escape for occupants. For the stories of a skyscraper higher than 30 m. above the ground, water spreading sprinklers must be arranged in order to prevent fire in such high stories in the skyscraper. However, no effective measures for positively preventing fire spreading in a skyscraper have been proposed.
The problem of promptly extinguishing fires in skyscrapers has been increasing recently in that the number of stories in skyscrapers has increased to several tens of stories. SUMMARY OF THE INVENTION
The object of the present invention is to provide a novel and useful method for promptly extinguishing fire occuring in a skyscraper.
Another object is to provide a novel and useful system for carrying out the method of extinguishing fires of the present invention.
The method of the present invention includes the steps of substantially completely shutting tight one of the fire fighting sections formed in a skyscraper including the zone in which a fire has started immediately after occupants of the fire fighting section have escaped therefrom, evacuating flame, smoke and air from the fire fighting section and injecting a fire extinguishing agent into the section to thereby promptly extinguish the fire.
In accordance with one feature of the present invention, the fire extinguishing agent may be a liquefied inert gas, such as liquefied nitrogen, or a bubble or foamable fire extinguishing liquid. When liquefied nitrogen is used as the fire extinguishing agent, the atmosphere in the fire fighting section is promptly made short of oxygen to starve the fire while the temperature in the section is promptly lowered below the flashing point of combustibles in the section. After replacing the atmosphere in the section by fresh open air once the fire has been extinguished, there are no harmful effects to articles in the section as might occur when sprinklers are used due to the fact that liquefied nitrogren leaves no contaminant on the articles after gasification thereof.
In accordance with the present invention, the evacuation of flame, smoke and air from the section in which a fire has occurred is effected at a low location, preferably at a plurality of low locations spaced from each other in the section, while the injecting of a fire extinguishing agent is effected at a high location above the level of evacuation. Preferably at a plurality of higher locations spaced from each other in the section, so that a uniform and effective distribution of the fire extinguishing agent in the section is insured by virtue of the evacuation of flame, smoke and air.
The system for carrying out the above method according to the present invention includes an overall control panel provided in a central control station in the skyscraper to which detecting means for detecting occurrence of fire in any of the fire fighting sections is connected. The control panel, upon receiving a signal from the detecting means, automatically issues demands in predetermined time sequence to closure means for the fire fighting section in which fire has taken place, suction means in that section and injection means in that section for the operation thereof, thereby permitting centralized automatic control for extinguishing fires.
A warning is issued from the control panel only to the story including the section in which fire has broken out upon receipt of the signal from the detecting means in order to prevent panic of occupants of other stories and to prevent the utter confusion which might be caused if all the occupants in the skyscraper received warning at the time of occurrence of a fire in only one section.